Drying apparatus



Oct. 13-, 1925. 1,557,422

C. C. COLBERT ET AL DRYING APPARATUS Filed Oct. 5, 1923 7 Sheets-Sheet 17722129722515: C/fiarfes 67500191? Oct. 13,1925.

c. c. COLBERT ET AL DRYING APPARATUS Filed Oct. 5 1923 '7 Sheets-Sheet-2 Oct. 13, 1925. 1,557,422 C. C: COLBERT ET AL DRYING APPARATUS FiledOct. 5. 1923 '7 Sheets-Sheet 5 Oct. 13, 1925. 1,557,422

C. C. COLBERT ET AL V DRYING APPARATUS Filed ct- 1923 v Sheets-Shut 4Oct. 13, 1925- c. c. COLBERT ET AL DRYING APPARATUS Filedpct; :5, 1925'7 Sheets-Sheet 5 Oct. 13, 1925;

C. C. COLBERT ET AL DRYING APPARATUS v Filed Oct. 5 1923 '7 Sheets-SheetPatented 0a. '13, 1925.

UNITED STATES PATENT oar-"lea.

cums c. commn'r AND enonea n. :ennsron. or anxnaa'r, INDIANA, assienoas'10 AMERICAN COATING MILLS,*OF ELKHART, INDIANA, A'CORPOBATION 0TINDIANA.

DRYING APPARATUS.

Application filed ttctoberfl, 1923. Serial No. 666,268.

fication.

Among other objects, the present invention is intended to provideapparatus for conducting a drying operation such as hereinafterindicated in an advantageous manner with regard to the materialundergoing treatment, as well as with regard to such I considerations aseconomy, rapidity of operation, and convenience of facilities.

The invention will be clearly understood by reference to one practicableform of apparatus embodying the same, shown in t e annexed drawings.

In said drawings:

Figs. 1 and 2 collectively represent a longi tudinal vertical section ofa drying room incorporating the illustrative apparatus, Fig. 1 showingthe first half and Fig. 2 showing the succeeding half thereof. Theseviews are partly diagrammatic, omitting mechanical details sufiicientlyshown in the remaining figures.

' Fig. 3 is a plan view of the receiving end of hang-up and conveyingequipment by which the material is exposed to drying action in saidroom.

Fig. 4 is a side view of the portion of said lli ang-up and conveyingequipment shown in i 3.

Fig. 5 is a plan view of the delivery section of said hang-up andconveying equipment.

Fig. 6 is a side view of the portion of the apparatus shown in Fig. 5.

Fig. 7 is a side view of an intermediate section of the hang-up andconveying equip- I ment.

Fig. 8 shows an alternative construction for sucha section of theconveying system as is represented in Fig. 7.

Fig. 9 is a vertical cross section on the line 9-9 of Fig. 4.

Fig. 10 is a detail side view of a dead rack rail.

Fi 11 is a cross section on the line 1111 of Fig. 10.

Fig. 12 is a detailed section on the line 12 12 of Fig. 7.

Fig. 13 is a section on the line 1313 of Fig. 7 a

'Fig. 14 is a detailed view representing successive folds of thematerial supported by pairs of sticks instead of by single sticks asrepresented in the preceding figure.

Fig. 15 is a side view showing a portion of the return conveyor for thesticks adapted fgr circulating two sticks at a time instead 0 one. I

'A web of material undergoing drying action is designated in thedrawings byv the numeral 1.

The apparatusselected for illustration is described in connection. withthe drying of coated paper board. A large quantity of continuous board,accumulated in undulatin'g formation or in a succession of open folds,1s exposed to drying treatment in said apparatus, which-is shownincorporated in a drying room 2. The drying process may progress as theboard moves along or through the room, while the freshly coated board isdrawn into the receiving end of the room and the dried board iswithdrawn from the other end for finishing the coated sur face of theboard and subdividing or reeling the finished product.

Contact with the coated surface of .the board should be avoided untilafter it is substantially dry. In this instance, board having a liquidcoating applied to a selected surface runs with its coated sideuppermost into and through the drying room, in which it (118 supportedfrom its under or uncoated s1 e.

In Figs. 1 and 4,-theboard is shown running into the receiving end ofthe drying room over rollers 3 and 4, and beinghung up in festoons ontransverse supports vided by so-called sticks 5.- These stlckspreferably consist of round wooden poles having their ends flattened to'rest on supporting or conveying means without tendency to turn or roll.They should be of sufficient diameter to provide ample supports fromwhich the board may hang wit out sharp bending. If desired the sticksmay be utilized in pairs or plurallties to provide said supports in thecase of hanging up very stifi board.

hang between the successively" resented sticks. This may be accomplishedy a air.

of endless elevating chains 6' arrange at opposite sides of" the boardand havingl suita y spaced lugs 7 for engaging an forwarding the sticks.Said elevatm chains pick up the sticks from curved gui es 8 arrangedcoaxially withthe lowersprocket wheels of the chains, and into whichguides the sticks are successively delivered by a, conveyor 9 ashereinafter explained.

The elevating chains deliver the sticks with the hun -up board toconveying means represented y parallel endless chains 10, spaced apartappropriately to support'the ends of the stic s while allowing thefestoons to hang between the chains and by successive sets or pairs ofendless chains 11, 12, 13, 14, .15, 16, 17, which successively carry thesticks with the hanging board, the

' sticks being transferred fromv one set of chains to another. Thesesuccessively arranged sets of carrier chains run at differentds aspresently to be described for c singing the spacing .of the sticks, withaccompanying contraction or expansion of the festoons of board carriedthereby.

'By running the first pair of carrier chains 10 at an appropriate speedin relation to the elevating'chains 6, the sticks carrying the hung-upboard are placed upon said chains 10 at desired intervals apart, preferably at fairly wide intervals so as to carry the festoons of board incomparatively dis tended condition for an initial drying treatment.

In this instance, the chains 11 to which the sticks are delivered by thechains 10 run at a somewhat slower speed than the preced ingchains,thereby receiving the sticks at closer intervals and contracting the ,festoons, go th t a-greater quantity of board, accumudrying action in theregion of the ersed by said carrier chains 11.

From the relatively slow' running chains room trav- '11, the stickscarrying the festoons of board are transferred to the chains 12 whichrun at a relatively'fast speed so as to take the sticks at wideintervals apart and thereby spread out or expand the festoons.

The succeeding chains 13 run at a relatively slow. speed for againspacing the sticks at closer intervals and narrowing the festoons. So onthrough the conveying system, the festoons are carried 1 alternatelyexpanded and contracted condition, and at varying rates ofspeed;the'sections 12, 14

and 16 of the conveying system running at relatively fast speed and thealternating sections 11,13, 15 and 17 running at relatively slow speed.

in closer formation, is submitted to As the drying process progresses,it is I desirable to reform the festoons in order to change the pointsof suspension of the board and expose the board differently to thedrying medium in the room. For this purpose t e board may be shiftedlongitutudinally of its supports by training the boardover one or moreoverhead rollers such as indicated at 18,19 and 20. These rollers arepreferably associated with the ,fast running sections 12, 14 and 16 ofthe conveyor system.

One of said fast running conveyor sections with an overhead shiftingroller is shownin Fig. 7, from which it will be seen that the boardtrained over the roller is withdrawn from the successively advancinsticks and is re-engaged by said sticks yond the roller-at differentpoints, from those previously engaged by the respective sticks. Thus thepoints of suspension of the board are automatically changed. The saidoverhead roller is power driven at appropriate speed for withdrawing theboard from the sticks and effecting a desired lineal advancement of theboard relative to the sticks.

To maintain desired spacing and correct transverse alignment of thesticks on the fast running carrier chains 12,14 and 16, as well as torevent dislocation of the sticks during-shifting of the board relativeto its supports, said chains are provided as shown in Fig. 7 withstick-engaging lugs 21, and certain retarding devices are arranged toresist movement of the sticks and thus maintain them in engagement withsaid lugs. The specific means shown is as follows: Rails 22 havinginclined or beveled front ends 23 are arranged beside said carrierchains and rise gradually above the level thereof but not above theprojections of the chain lugs ,21. Above these rails are hanging bars 24connected bybolt and slot connections 25 to hangers I26, permitting.said bars to be raised. A stick 5transferred from p the slow runningchains 11 to the fast running chains 12 rides up the beveled ends 23 ofthe rails 22 and against the under beveled ends 27 of the upper bars 24.This causes the stick to pause until its ends are engaged by an oppositepair of the chain lugs 21 on said fast running chains 12. These chainlugs then push the stick between the rails 22 and upper bars 24, thelatter being elevated by the stick. I Said upper bars may have theirunder surfaces recessed at 28 to relieve the sticks of the weightof-said bars.

transverse alignment of the sticks on the arallel chains is maintained.'After passmg under the overhead roller and to position for reengagementof the board, the stick may be caused to ride over inclinedobstructors-30, thus insuring its ali gnmentby maintaining it againstthe chain ugs 21. it will board. In Fig. 1, manifolds for supplying beunderstood that each board shiftingsection of the conveying system isequippe with meansof the character just described.

Fig. 8 shows an alternative construction for a section of the conveyingsystem in which shifting of the board takes place. In this alternativeconstruction, successive sets of carrier chains 12 and-12 replace thecarrier chains 12 of Fig. and the inclined obstructors 30 are arrangedbeyond. e juncture of said chains. Both sets of chains'12 and 12 areequipped with cna'm lugs 21, but the arrangement is such that the chains12", whether travelling at the same speed as the chains 12 or otherwise,engage the stick after its delivery from the chains 12 and while" it ispausing on the obstructors 30.'

Otherwise the construction is the same as that of Fig. 7. By apropriatespeed adjust: ment ofthe chains 12" and 12 in relation to the speed ofthe overhead roller, or by appropriate arrangement of the respectivechain lugs, or both, theperiod of pause of the stick on the obstructors30 maybe predetermined to client resuinption of travel of the stick inreengagement with the board beyond the roller at the desired point onthe board. This construction also lends itself to variousadaptations inthe relative spac v ing and speeds of conveyance'of the fes-- toons inadvance of and beyond the shifting Points From the" foregoingdescription, will festoons or folds is conveyed through the drying room:by a succession, ofconveying. means ruimlng at alternate rates ofspeeds,

so as alternately to contract andspread out the festoons to dryingfaction; while the conveyance of the board in-thismanner is accompaniedby one or more shiftings of the board to change" its'points ofsuspension, or 1n other words to cause the board'to hang f on the sticksfrom portions which were previously suspended between the sticks. Theseactions promote eiiicient and uniform drying of the board; while thesuccessive shifting of the. points of support prevents formation ofundesirable bends or ruflles in the board and checking of its coatedsurface.

A heating system for the drying room is represented by a pair ofoverhead longi-.

tudinal hot air ducts 31 having slots 32 in "their under sides forblowing-heated. air

' upon or toward the upper or coated side of the board, and a' number ofnozzles 33 in the floor ofthe room forv blowing heated air against theunder or uncoated side'of the hanging in V waiy. d l n drying coatedboard, it isdesirable to.

subject the board to a gentle and gradual preliminary drying, withoutexposure of its coated surface to direct action'of heat currents, andthen. to submit the board to a more pronounced drying action in thepresence of heat currents directed toward its coated side. By thistreatment there is obtained an advantageous preliminary evaporation ofmoisture and seasoning of the body of the board, and its coatingacquires a setting and consistency adapting it to withstand the ensuingmore severe drying action.

It will be observed by reference to Fig. 1, that the heating system-ofthe illustrative room is so arranged that the hanging festoons ofboard'are conveyed a considerable bottom hot air nozzles 33, and areconveyed a further considerable distance before coming within the rangeof the overhead hot air ducts 31; and that the festoons are within I,-the range of both the overhead and underneath heat blasts for alimited distance, after which the drying of the board is continued bythe-overhead blasts.- The specific arrangement shown is such, that thefestoons first encounter the action of the underneath blasts .whileconveyed in comparatively distended condition by the first set oflongitudinal carrier chains 10, and are subse- Y quently acted upon bysaid blasts while conveyed in closer folded condition by the carrierchains 11. v

This arrangement providesin the-drying room a region of preliminarydrying,i-the action of which progresses in'two general stages andinseveral steps. First, the freshly coated board is conveyed with itsfestoons fairly distended or spread through a substantial distanceWithout submission to drying influence other than the relativelyquiescent and temperate atmosphere of the room, accomplishing a gentleinitial drying and setting of the coated surface of the.

board. Then the festoons come within the range of the underneath heatcurrents, blowing upwardly against the under or uncoated side of theboard and into the spaces between the festoons, warming the body of theboard and further advancing the drying. I This stage of treatment,commencing while the condition, continues in the illustrative room whilethe festoons are more slowly moved in festoons are moving in relativelydistended.

toons, the board is differently exposed in contracted condition by thecarrier chains conveyed in comparatively contracted con-' d1t1on by theslow running chains 11. As i the hanging board is further conveyed along11, during which step there is a relatively greater quantity of theboard maintained for a relatively longer period within the range of theunderneath blasts. Thus an effectual progressive drying ensues inadvance of exposure of the coated surface of the board to the directaction of impinging heat currents.

According to the specific arrangement shown, the festoons are broughtwithin the range of the overhead hot air ducts 31 while the drying room,by a number of successive sets of carrier chains, it is exposed undervarying conditions and differently presented to the currents of heatedair discharged by said overhead ducts; and also continues for a certaindistance to be exposed to the heated air currents ascending from thefloor nozzles In the regions of the drying room traversed by the slowrunning sections 11, 13, 15, 17 of the, conveying system, extensiveaccumulations of the board in narrow festoons are maintained, so thatthe volume of heatmg medium acting during any given interval in theseregions is expended upon a rela- .ti vely large quantity of material;while given portions of the material are exposed in these regions forrelativel prolonged periods. Said regions may appropriately referred toas zones of protracted drying.

In the alternating regions of the fast running conveyor sections 12. 14,16, the board in expanded or distended condition is ex sed forrelatively briefer intervals, durmg which'thevolume of heating mediumacts upon relatively s'mall quantities of the board. Thus the dryingaction per unit of tracted drying. Furthermore the drying effect in theregions of the. fast running conveyor sections is promoted by thespreading out of the board, and still further accentuated if the boardis run over the overhead shifting rollers in proximity to the overheadair ducts. These regions may accordingly be referred to as zones ofaccelerated drying.

By changing the points of sus'pension of the board, involvingreformation of the. fessuccessive drying stages, bringing portions whichformed lower or intermediate lengths of the festoons in one stage intoposition for.

' head shiftin case of board coated with a'thin or continuallyadvancingthe degree of dryness of the board.

-B a ro riatel -reformin the festoons o y pp p y g efiecting appropriatelongitudinal shifting of the boarda suflicient the board may be driedsubstantially uniformly throughout its number of times,'.

length. I y

Asthe boardmoves rapidly over an overroller, its coated surface isuniformly su jected to the action of the hot air blasts in closeproximity to the ducts 31,

as will be apparent from Fig. 13.. This again contributes to eiiicientand uniform drying. It may however be unnecessary or undesirable in somecases, depending upon the character of the board under treatment and thenature and thickness of the applied coating, to run the board over allthe overhead rollers, or to expose'its cpated surface" to close actionof the hot air-blasts in every 'zone of accelerated, drying, andespecially the first such zone. For mstance, 1n some cases the liquidcoating may be in too fresh or wet a condition for close exposure to hotair blasts while in the region of the drying room traversed by thechains 12 and in the drying composition close exposure to, air currentsin all of the zones of accelerated drying might result in too severe orsudden drying, renderingit expedient to carry the board under'oneor moreof theoverhead rollers, or to efiect the shifting without such closeexposure. For instance, the bottom discharge slots of the overhead ductsmay be closed at these portions ove'rlyin a roller, so as topermitrunning the boar roller for shifting purposes without accompanyingsevere drying treatment.

With the heating arrangempnt s'liown, theo drying m a board under oes -aperio medium disc arging against lts uncoa'ted side, overlap in withaperlod of by a medium 'sc argm side of the board. e overlappingmterval, in which the board iS'ZISimIfltQIIQOUSl over such toward theexposed to the action of both the descen ing and ascendin drying whichin this instance in successivesteps or stages in the region of thedrying room traversed in part by the slow currents of, ;;li e ated= air,i represents a perio of relatively'prpnouncedn5 cending and descendingcurrents of heated air, after the period of progress'ive preliminarydrying heretofore described the board is brought to a condition inwho it madequately responsive to the succeeding stages of drying action,which 1n the mstanceare continued by the descending j currents of heatedair upon the coated side-of theboard until and, if desired, during theaccumulaassociation with. the

tion of the'board in the delivery end of the dr groom.

- he operations described provide a method by which coated paper boardis advantageously dried by progressive steps or sta es of drying actionof different kinds an effects, including recurrent heat treatments undervarying conditions in the presentationof the board thereto, forobtaining eflicient and substantially uniform drying in the timeinterval between the coating and finishing of the board.

From an accumulation of the dried board hanging in the delivery end ofthe apparatus, either on the chains 17 or a succeeding set of chains orsupporting means associated therewith, the board may be continuouslywithdrawn for calenderin or finishing its coated surface and subdividingthe finished product into cut sheets. It may be desirable to varyaccumulation to accommodate conditions arising in the operation of theplant in which the drying room is included. For example, where coatedboard is being continuously manufactured and runs continu- .ouslythrough the coating machine except for such occasional interruptions asmay e required for changing coating brushes or colors or for otherpurposes, it is desirable in event of temporary interruption of asucceeding unit of the plant to permit continuing accumulation of theboard in the deliver end of the drying room; and, on the ot er hand, inevent of interruption 'of the coating operation, with an accompanyingstoppage ofv the dryin room conveying systern, it is desirable to ave areserve su ply of the hanging folds of dry board rom which the board maybe contniuously'withdrawn for the subsequent finishing and subdividingoperations.

- For maintaining such ,a reserve supply, or permitting continuedaccumulation n event of any interruption or slowing of operation in asucceeding machine or unit of the plant, there is provided preferably inveying system, in this instance the carrier chains 17, a so-called deadrack presently to be described. This dead rack, shown more clearly inFigs. 5, 6, 10 and 11, comprises longitudinal rails or bars 37, onebeside each of the parallel chains. Said dead rack bars are supported soas to permit them to be depressed below the levels of the carrying runsof the chains, in the position shown in Figs. 2 and 10, which is theirnormal position, or to be elevated above the chains 111 the positionindicated by dotted lines in Fig. 10. The rear or receiving ends of saidbarsare beveled or inclined as indicated at 38 so that, when the barsare in the elevated position shown in Fig. 6, the sticks 5 carrying thefestoons of board may ride onto the dead rack bars, after which thesticks will be ast section of the con-.'

pushed along said barsone by the other. Thus a large number of festoonsmay be collected inclose assembly. The delivery.

ends of the dead rack bars are shown pro-v vided with curved extensions39 whichin elevated osition of the bars will overlie the sprocket wheelsat the delivery ends of the carrier chains and permit the sticks to bedischarged from the delivery end of the dead rack.

In the specific construction shown in the drawings, the dead rack bars37 are pivoted conveying system. One ofthe cranked portions of the crankshaft 42 is provided with an operating lever 45 which may be operated inone direction or the other by pull I cords 46 and 47. By meansof thelever 45, the cranked portions of the crank shaft ma be moved to asition of dead-centers wit respect to the arings of the crank shaft,th'us supporting the dead bars 37 in elevated position, and the arts maybe maintamed in this position y maintaining the. pull cords 46 and 47taut and fastening them in any convenient position. p At the deliveryend of the conveying sys tem, means is provided to facilitate withdrawalofthe dried board from the accumulated supply hung up' therein without.liability of muring'or tearing the board.

For this purpose the last pair of carrierv chains 17 deliversthe sticks5 for carrying the suspended folds of board upon declined conveyorchains 48 from whichthesticks are delivered to declined rails 49arranged beside said chains 48 and graduallyrising to an elevation abovethe chains to permit the sticks to ride from said chains onto saidrails. The hanging board is" withdrawn from the sticks resting on. saidrails 49,

while the sticks slide down the rails and are discharged.

If the dead rack bars 37 sticks 5 will ride from the chains 17 onto aredepressed,the I the declined chains 48 and thence onto the rails 49, andthe'sticks will be caused to slide down the rails under the drag of'thehanging board as it is withdrawn from the dry- 7 ing room. If thewithdrawal of the board shouldbe interrupted by tempo ary interruptionin the operation of a succeeding unit of the plant, the sticks with theban 'ng folds of board may crowdtogether an accumulate on the declinedrails 49 as shown in Fig. 6. If the interruption of withdrawal is for alonger period than that which can be accommodated by the accumulating caacity of said rails, while the coated board is being continuouslysupplied to and hung up in the conveying stem, "thedead rack bars 37 magallowing t carrying the festoons to collect .in crowded assembly on'saidbars; U on resumption of be elevat as before explained,

. o eration in the succee ing unitof the with ant with accompanyin pdrawal of the board from the'dryin room the dead rack bars may bedepresse to a ow. the sticks-to rest again upon the con've chains 17which will deliver the speeded-up' to e'fi'ect a more rapid withdraw-'tem. Besides t i also retard the travel of the sticks and oifer crowsticks onto the chains 48 and thence onto-the declined rails 49; and theoperation of said succeedingunit may be temporarily al of the boarduntilthe excess accumulation is drawn off and normal conditionsoare re- Itwill beseeii that the decline rails 49- 'aiford provision in addition tothe dead rack for variation of accuiinulatingcapacity i i the deliverend of the conveyin sysfunction, said-rai 49 a desirable frictionalresistance to the move- 5 ment. of the sticks as the sag" ingj board iswithdrawn over the sticks. urthermore, under various conditions, theserails persticks and crowded festoons of ."m'itthe sticks to accumulateone behind another during and until the withdrawal of the board fromvfolds suspended between successive sticks, thus-avoiding continuedtravel of the sticks du the withdrawal.

The pull of the oard as it is withdrawn from the ban -up apparatusdragsthe sticks down the dec ined rails 49 and causes'them to slide downthe'rails and to be" discharged. There maybe frequently a numberofsticks in elose relation-on the rails, the pull\ of the boardfrom'di'agoging' ar too rapidly down the rails, and to prevent jerkingof the board from the successive folds,

To. prevent there is provided asuspended orswi'ngin wiper 50, such fo'rinstance asa s'heet o carpet. or other suitable flexible material,

= which rests upon andndrags against the board and exerts a retardingaction on the'stieks. Thus the board is withdrawn .against theresistance of the swinging wiper "50 and of .the sticks in frictionalcontact contributing to.

with the declined rails 49,

- smooth and even withdrawal. I

roller 51, while'the sticks 5 The board may be withdrawn from thedelivery end of the apparatus over a guide ass from the declined'rails49 onto the de ivery ends of the chains 48 and are deposited in amagazine comprising parallel guides 52, which e successivelyadvancing'sticks resumption of the 'structors 59 are placed in the sticksmustride, thus 1 the number of stic time according to conditions existing asto the 1 'shown in Figs. 1 to 13, the stic employed sin tion, t e lowerends of the magazine guides are shown constructed with feet 55 tosup-.port the. sticks and with ejecting open: ngs- 56.

having; ejecting lugs 54'. To permit ejec-' The ejected sticks arecarried bylthe re-- turn conveyor 9 back to the receiving end of thedrying room. .Said return conveyor is shown as apair of parallel chainsprovided at suitable intervals with lugs 57 for en ing and forwardingthesticks. As the sticks are successively ejected from the magazine,swinging bumpersfl58 knock against the sticks to steady them and preventthem from being thrown too far. As a means for strengthening or aligningthe sticks transverse y of the return conveyor, inclined obthe path ofthe sticks, over which ensuring their lodgment against the lugs 57 onthe return conveyor chains and their delivery to the receiving end ofthe hang-up and conveying equipment in propertransverse alignment.

At said receiving end, the return conveyor 9 delivers the sticks intothe curved guideways 8 associated" with the lower sprocket wheels of theelevating chains 6 which pick up the successively presented sticks andcarry them into position for hanging up the infeeding board as beforeexplained. Thus the sticks are ,circulated back and forth through theapparatus, and a reserve supply of the sticks is maintained in themagazine 52 to permit variation in ks employed at a given theaccumulation of the board in the delivery end of the apparatus.

In the organization of the apparatus s 5 are ly as supports for thehanging board. at a time from the magazine guides 52, at such intervalsof time as to be successively engaged and forwarded by the successive In.57 I of the return conveyor .9, and are de ivered one at a time into.the' curved guides 8 at proper periods to be picked up by thesuccessively advancing lugs 7. of 1 the elevating chains. Should it bedesired to use the sticks in pairs or groups as individual supports forthe festoons, as indicated in- Fig. 14, the ejecting wheels 53 may beequipped with additional ejecting ence'the sticks are ejected one lugsor have their ejecting lugs arranged in pairs, as shown in Fig. 15, soas to cause. ejection of the sticks in pairs or groups between thesuccessive lugs of the return conveyor, which will deliver the ejectedpairs or groups of sticks one after another into the curved gi'uideways'8 in proper sequence to be picke up by the successive lugs of theelevating chains.

- The means illustrated for driving the ing pairs of carirer chains10,11, 12, 13, 14,

' shafts 60.

.An additional sprocket w on the shaft for use in changing ratios 15, 16and 17 are driven at their respective delivery ends by a number ofoverhead (Figs. 3 to 7.) Thedrivin sprockets for these successive airs ochains are mounted on stub siafts 61 driven by caring 62 from saidoverhead shafts 60. eside the driving sprockets for each pair of chains,and loosely mounted on the same stub shafts which carry the drivingsprockets, are idle sprockets for the receiving ends of the succeedingpair of chains. For instance, as shown in Fig. 9, driving sprockets 63for a preceding pair of conveyor chains, and driven. sprockets 64 for asucceeding pair of conveyor chains, are shown coaxially mounted on thestub shafts 61; the said driving sprockets being fast on said stubshafts and the said dr ven sprockets being loose thereon. Thus each pairof carrier chains runs from idle sprockets to and around drivingsprockets coaxial with the idle sprockets for the next pair of chains.This description applies to all of the overhead carrier chains exceptthe declined delivery chains 48 which run from driving sprockets coaxialwith the driving sprockets of the preceding carrier chains 17.

The several overhead shafts 60 may be driven by a system of chains 65from'a shaft 66 (Figs. 3 and 4). The transmission chains 65 mayrun fromone shaft 60 .to another around sprocket wheels of appropriateproportions to maintain the desired relative rates of speed of thesuccessive pairs of carrier chains. For instance, in

ig. 9, the overhead shaft 60 is driven by a chain engaging the sprocketwheel 67 and communicates power to a succeeding shaft by a chainengaging the sprocket wheel 68. eel 69 is shown of speedpf the,succeessive sets of carrier chains. I I

As shown in Figs.- 3 and 4, the return conveyor chains 9 are trainedaround driving sprocket wheels on a shaft 70 which is driven b chains 71from the same shaft 66 that drlves the transmission chains '60 for thecarriers which convey the sticks and hanging festoons of board throughthe drying room. At the delivery end of the drying room (Figs. 5, 6 and15) the return conveyor chains are trained around sprockrats on a shaft72, from which the ejecting wheels 53 may be driven by a chain transmission 73 or other suitable connection.

The shaft 66 (Figs. 3 and 4) is driven by a chain 74 from a shaft 75below the floor of the drying room; and the last mentioned :cludinchecks or creases, ma

shaft 75 is driven by a chain 7 6. from a suitable transmissionmechanism,including, if desired, a Reeves variable speed transmission,which in turn may be driven from any suitable source of power or from atransmission connected with the coating machine whereby the hang-up andconveyin system of the drying room may be operate in synchronismtherewith.

By varying the speed of the elevating chains 6 in relation to the rateof delivery of the board to the apparatus, the intervals of hanging upthe board in festoons may be adjusted, thereby varying the amount ofboard in individual festoons and according ly varying the amount ofboard exposed to drying action. Such speed variation may be accomplishedeither by speed adjustment of the entire hang-up and conveying sys tem,or by changing the sprocket gear ratios of the driving and drivensprockets of the elevating chains. A slight reduction or increase inspeed results in a large increase or reduction in the amount of materialhung up.

The various conveying chains of the drying room conveying system may runover suitable supporting rails, and may be. asso ciated with suitableside guides to prevent displacement of the sticks longitudinally,

or in a direction transverse of the board. Such supporting rails for.certain of the chains are shown at 77 in Figs. 9 and 13. Side guides toprevent endwise displacement of the sticks are shown at 78 in saidfigures. Idle sprockets or guide wheels for the lower runs of conveyingortransmission chains are shown at 79 in Figs. 4, 6, 9 and 13.

The overhead rollers 18, 19 and 20, over which the board may be trainedfor shifting it longitudinally to change, the points of suspension, maybe driven by sprocket chains 80 from certain of the stub shafts 61. .InFig. 13, one of such overhead rollers is shown, the shaft 81 of saidroller having a sprocket wheel 82. for engagement by its driving chain.

As the board runs from the drying room, it may be ex d to the action ofhot air blasts. disc arged from suitable pipes, one of which is shown at83 in Fig. 6, for the purpose of, additional or superdrying action, andto heat thecoated surface advantageously for the finishing operation.

By employing an apparatus and method embodying ali of the features ofthe present invention, a product thoroughly and substantially uniformlydried in proper condition; and substantially free of flaws in: beobtained. The ilustrative apparatus a so eliminates objectionable andinconvenient handling. of the board or its supports, and is adapted foreconomical and rapid manufacturing practice. The structure of theapparatus is such that duplicates of desired sections may be interposedwhere and if desired.

Obviously the present invention is not limited to the specific detailsof construcinvention, we claim 1. A 'web drying apparatus comprising, 1ncombination, a drying enclosure; successively arranged means includingalternating means running at alternating speeds. for

continuously moving the, web undergoing treatment through the dryingenclosure while maintaining the web in undulating 'formation andproviding alternating distefnded and contracted accumulations there- 02. A drying apparatus comprising, in

combination, .a' drying enclosure; means for projecting heat currentstransversely of the enclosure; and means for moving a quantit ofmaterialin undulating formationthroug the enclosure said last namedmeansacting to present the undulations in alternately expanded and contractedcondition in different zones of the enclosure while 'efiecting linealmovement of the material to refrom the festoons.

3. A jdrying apparatus comprising, in

. combination, a drying enclosure; means for maintaining a quantity ofcontinuous material in undulating formation in said enclosure; 'meansfor progressively drying said material in successive stages of dryingaction of different effects; and efiecting a plurality of reformationsof the undulations to present the material differently in successivedrying stages. 1

4. A drying apparatus comprising, in combination, means for su portin aweb in undulating formation while un ergoing drying action; and meansfor efi'ecting a succession of alternating expansions and contractionsof its undulations.

.5. A drying apparatus comprising, in combinationi, means for supportinga web in undulating ormation while undergoin dry: ing action; .and meansfor successive? forming the festoons while maintaining them inalternately spread out and contracted condition. y

6. A drying apparatus comprising,. in combination, supports carrying aweb in festoons; and means acting uponv said supports to change thepoint of sus ension of the web thereon for carrying the estoons inrepeatedly changi'ngconditions forexposure to drying action.

7. A. web drying apparatus comprising, in combination, means foraccumulating the web in undulations and exposing said undulations todrying action;- and means for varyingthe accumulating capacity of theapparatus.

8. A web drying apparatus comprising, in combination,"means foraccumulating the web in undulations and' exposing the same to dryingaction, while supplying the web to and withdrawin it from the apparatus;

and means of varia 1e ca acity for accumulating the undulations o thedried web.

In testimony names to this s ecification.

HARLES C. COLBERT.

GEORGE E. PRESTON.

whereof, we have signed our

